Secure access to physical resources using asymmetric cryptography

ABSTRACT

Digital certificates are signed by a server&#39;s private key and installed at lock controllers that restrict access to physical resources. The server&#39;s public key is distributed to lock controllers and to mobile electronic devices operated by users who are given access to the physical resources. Lock-access data is digitally signed by the server&#39;s private key and provided to mobile electronic devices to facilitate access. The lock controller validates lock-access data and grants access conditionally based on time, version, and/or identity data provided within lock-access data. The use of certificates reduces the need to rely on a security scheme specific to the network. Lock controllers can also broadcast status notifications, so that updates and log data can be securely communicated with the server using mobile electronic devices as a proxy. The system is highly scalable, as each lock controller need not track the full scope of access permissions.

FIELD

This invention relates to security, more specifically, to secure accessto physical resources.

BACKGROUND

Known techniques for securing physical resources, such as buildings,include providing an electronic lock to a door and then configuring thelock to respond to the presence of an access card, key code, or similar.More recent systems use smartphones to open electronic locks. In suchsystems, the electronic lock tends to be wired for power or have easilyreplaceable batteries. In addition, reliable control signalling to theelectronic lock is often a requirement.

Conventional systems are ill-suited for securing physical resources thatare not readily wired for power and data. Such resources are often atremote locations or are infrequently accessed. Running data and/or powerto such resources can be prohibitively expensive and complicated. Assuch, these kinds of resources are often secured using physical keys,which can be easily copied, lost, or stolen.

Moreover, many conventional systems, such as those that are used inresidential applications, often take for granted the physical exposureof the lock to augment the relatively simple security technologyprovided. That is, it is often thought that a typical residential “smartlock” need only be as secure as the deadbolt that it replaced, assomeone trying to gain unauthorized access to a residential smart lockis a comparable threat to someone trying to pick a deadbolt. This maysuffice for residential applications. However, for remote orinfrequently accessed physical resources, those trying to gainunauthorized access have much more time and ability to do so withouttimely detection. Hence, conventional systems, particularly those thatcan be categorized as residential smart locks, are incapable ofadequately protecting such resources.

SUMMARY

According to various aspects of the present invention, a server stores apublic and private key pair. Digital certificates are signed by theserver's private key and installed at electronic lock controllers thatrestrict access to physical resources. The server's public key isdistributed to the lock controllers and to mobile electronic devicesoperated by users who are to be given access the physical resources.When a mobile electronic device enters the vicinity of a lockcontroller, the digital certificate of the lock controller is used asthe basis for encrypted communications between the mobile electronicdevice and the lock controller. Lock-access data that has been digitallysigned by the server's private key is transmitted to the mobileelectronic device to provide to the lock controller to gain access tothe physical resource. The lock controller validates the lock-accessdata and grants access conditionally based on time, version, and/oridentity data provided within the lock-access data.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate, by way of example only, embodiments of thepresent invention.

FIG. 1 is a diagram of a system for providing secure access to aphysical resource.

FIG. 2 is a diagram of an access control server.

FIG. 3 is a diagram of data structures for users and lock controllers.

FIG. 4 is a diagram of a wireless mobile device.

FIG. 5 is a diagram of an electronic lock controller.

FIG. 6 is a diagram of a setup process.

FIG. 7 is a diagram of an unlocking process.

FIG. 8 is a diagram of an updating process.

FIG. 9 is a diagram of a log capturing process.

FIG. 10 is a diagram of another electronic lock controller.

DETAILED DESCRIPTION

The present invention aims to solve at least one of the problemsdiscussed above. Specifically, the present invention assigns uniquecryptographic keys to different electronic locks, so that encrypted andauthenticated channels can be established with mobile devices of userstrying to gain access to physical resources protected by the electroniclocks. Digital signatures are used to help mobile devices avoidcommunicating with imposter locks and to prevent mobile devices fromusing forged access data to open electronic locks. Further aspects andadvantages of the present invention will be apparent from the belowdetailed description.

FIG. 1 depicts a system 10 for providing secure access to a physicalresource according to the present invention. The system 10 includes anaccess control server 12, an electronic lock controller 14, and aplurality of wireless mobile devices 16. The lock controller 14 unlocksa physical lock 18 that restricts access to a physical resource 20.Unlocking is based on access requests made by the wireless mobiledevices 16, as controlled by access permissions managed by the accesscontrol server 12. The system 10 can include any number of accesscontrol servers 12, electronic lock controllers 14, and wireless mobiledevices 16 to restrict access to any number of physical resources 20.The present invention includes asymmetric cryptographic techniques thatallow for flexible, secure, and readily configurable control of accessto the physical resource 20.

The physical resources 20 guarded by the present invention may besituated at remote geographic locations. Examples of such resourcesinclude cell tower shacks, oilfield installations, constructionequipment and sites, remote industrial facilities, an similar. Thephysical resources 20 guarded by the present invention may includeindustrial or commercial fixtures, such as storage cabinets, lockers,storerooms, yards, and similar. The present invention is particularlysuited for physical resources that are normally accessed from one side(e.g., a shack that is not normally occupied, a cabinet, etc.). Inaddition, the present invention is particularly suited for physicalresources that are located remote from grid power and wired computernetworks or that are not particularly suited for connection to gridpower and wired computer networks. A salient example of a physicalresource 20 is a cell tower shack that contains valuable equipment suchas network devices and high-capacity batteries. That said, the precedingare merely examples of the types of physical resources 20 suitable foruse with the present invention and they should not be taken as undulylimiting.

The wireless mobile devices 16 are configured to connect to the accesscontrol server 12 via a computer network 24. The computer network 24includes one or more internet protocol (IP) networks, such as anintranet, a local-area network, a wide-area network, a virtual privatenetwork (VPN), a Wi-Fi network, the internet, and similar. Any suitableprotocol, such as TLS and HTTPS, can be used for secure datacommunications. The computer network 24 can include cellular/mobilenetwork infrastructure 22 that operates according to any type ofcellular/mobile network technology and standard (e.g., 2G, 3G, 4G, GSM,UMTS/UTRA, HSPA, LTE, CDMA, WiMAX, etc.) that provides for relativelylong-range wireless communications. Generally, the computer network 24uses grid power and has wired components (e.g., Ethernet, fiber optics,etc.).

The access control server 12 stores a public key 30 and a correspondingprivate key 32. The keys 30, 32 may be generated according to anyasymmetric cryptographic scheme or equivalent cryptographic scheme. Forexample, NIST-approved elliptical curve cryptography can be used. Theaccess control server 12 further stores a database 34 that stores aplurality of user accounts for users of the wireless mobile devices 16to be provided with secure access to the physical resource 20. One ormore administrator computers 38 can be provided to manage the accesscontrol server 12, and particularly manage the user accounts and whichusers have access to which physical resources at what times.

The lock controller 14 stores a digital certificate 36 that includes apublic key and a corresponding private key for the particular lock 18.Each lock controller 14 has its own unique digital certificate 36. Thepublic and private keys of the lock controller 14 also accord to theselected asymmetric cryptographic scheme. Keys of any suitable bitlength (e.g., 64-bit, 128-bit, 256-bit, etc.) can be employed based onthe desired level of security. In addition, the digital certificate 36has been previously digitally signed by the private key 32 of the server12. Signing of the digital certificate 36 with the private key 32 of theserver 12 is preferably done in a secure environment, such as at afactory that manufactures lock controllers and provisions access controlservers. The lock controller 14 further stores the public key 30 of theaccess control server 12.

The wireless mobile devices 16 are carried by users who are to begranted access to the physical resource 20. Access permissions areassociated with user accounts in the database 34. A user logs intohis/her account, using for example a unique username and password, fromtheir wireless mobile device 16 to obtain from the server 12 lock-accessdata 40 that grants access to the physical resource 20 or grants anotherpermission with respect to the lock controller 14.

In this embodiment, the wireless mobile device 16 and electronic lockcontroller 14 are configured to mutually connect for data communicationswhen within local vicinity of each other. That is, each of the wirelessmobile devices 16 and the electronic lock controller 14 has alocal-range communications interface, which can include a chipset and/orantenna/transceiver operable according to any suitable short-rangewireless communications scheme (e.g., Bluetooth, Bluetooth Smart,Bluetooth Low Energy or BLE, Wi-Fi, ZigBee, Google Thread, Near FieldCommunication or NFC, etc.), short-range audio communications scheme,short-range infrared communications scheme, or similar technology. Theparticular short-range communications scheme selected is notspecifically limited, though its range is shorter than that provided bythe computer network 24. However, because the present invention concernsgranting physical access to remote physical resources that may not haveaccess to grid power, it is contemplated that shorter-ranged schemeswill generally be more advantageous due to reduced power consumption.The presently preferred short-range communications schemes includeBluetooth and BLE.

In other embodiments, the wireless mobile device 16 and electronic lockcontroller 14 are configured to mutually connect for data communicationsover the computer network 24 (e.g., over the internet).

Concerning operation of the system, in overview, the server 12 digitallysigns lock-access data 40 specific to the user and the lock controller14 using its private key 32 prior to transmitting the lock-access data40 to a wireless mobile device 16 of a user who wishes to gain access tothe physical resource 20. The wireless mobile device 16 obtains the lockcontroller's server-signed digital certificate 36 from the lockcontroller 14, when in vicinity of the lock controller 14, and validatesthe authenticity of the certificate 36, and thus the authenticity of thelock controller 14 itself, using the server's public key 30. Oncevalidated, communications between the wireless mobile device 16 and thelock controller 14 can be secured on the basis of the lock controller'sdigital certificate 36. The wireless mobile device 16 can safely encryptthe lock-access data 40 using the lock controller's public key andtransmit the encrypted lock-access data 40 to the electronic lockcontroller 14, which can use its private key to decrypt the lock-accessdata 40. The lock controller 14 can validate the authenticity of thelock-access data 40 using the server's public key 30. If the lock-accessdata 40 is successfully validated, the lock controller 14 performs oneor more operations defined by the lock-access data 40, such as unlockingthe lock 18. Similar processes can be used to allow the server 12 toupdate settings of the lock controller 14, to communicate data (e.g.,log data) from the lock controller 14 to the server 12, and to confirmthat the lock 18 has been properly locked after access to the resource20 is completed. The above process can also be used to lock the lock 18,although it is contemplated that unlocking the lock 18 will generally bemore of a security concern.

It is advantageous that the wireless mobile device 16 and the lockcontroller 14 communicate using a digital certificate assigned to thelock controller 14. The server 12 signs both the lock-access data 40 andthe lock controller's digital certificate 36, advantageously allowingthe lock controller 14 and the wireless mobile device 16, respectively,to validate the authenticity of the lock-access data 40 and the lockcontroller's digital certificate 36. This allows the lock controller 14to detect forged lock-access data and respond appropriately by, forexample, not opening the lock 18, logging an unauthorized accessattempt, issuing an alarm, or similar. In addition, the wireless mobiledevice 16 can detect an impostor lock controller and respondappropriately by, for example, not transmitting the lock access data,notifying the server 12 of the location of the unauthorized lockcontroller, and similar. The present invention will be discussed infurther detail below and additional aspects and advantages will becomeapparent.

FIG. 2 shows a block diagram of the access control server 12. The server12 is one example of a server that can be used with the system 10. Theterm server as used herein refers to a single server or multiplecooperating servers.

The server 12 includes a network interface 50, memory 52, and aprocessor 54. The network interface 50 is configured for bidirectionaldata communications through the computer network 24. The networkinterface 50 includes a network adaptor and driver suitable for the typeof network 24. The memory 52 includes any combination of read-onlymemory (ROM), random-access memory (RAM), flash memory, magneticstorage, optical storage, and similar for storing instructions and dataas discussed herein. The processor 54 includes one or morecentral-processing units (CPU), microcontrollers, microprocessors,processing cores, field-programmable gate arrays (FPGA), and similar.All or some of the memory 52 may be integrated with the processor 54.The processor 54 and memory 52 cooperate to execute instructions tocause the server 12 to perform the functionality discussed herein.

As mentioned above, the server 12 stores the server's public and privatekeys 30, 32 in addition to the database 34. The database 34 stores usersaccount data 56 and lock data 58.

The server 12 further includes a lock-access engine 60 that isconfigured to generate lock-access data 62 based on the lock data 58 andthe user account data 56 to allow access to specific physical resourcesby specific users at specific times. The lock-access engine 60 isfurther configured to digitally sign lock-access data 62 using theserver's private key 32. Lock-access data 40 discussed above is anexample of lock-access data 62. The lock-access engine 60 is configuredto manage log ins by users and transmit appropriate lock-access data 62via the network interface 50 to respective wireless mobile devices 16.In addition, the lock-access engine 60 can be configured to deploy theserver's public key 30 to the wireless mobile devices 16.

The server 12 maintains the lock-access data 62 in association with theplurality of user accounts stored as user account data 56. Thelock-access engine 60 is configured to transmit lock-access data 62 to aparticular wireless mobile device 16 upon the wireless mobile device 16establishing a connection to the server 12 via the network interface 50and the user of the wireless mobile device 16 successfully logging intotheir account.

The lock-access engine 60 is configured to handle continued access tophysical resources while at the same time allowing for accesspermissions to be revoked. This can be achieved in several ways. In oneexample, the lock-access engine 60 periodically regenerates thelock-access data 62 with updated permitted access schedules, where suchregeneration can be ceased for specific users in order to deny access tothe physical resource to such users. Users log into the server 12 toobtain fresh lock-access data 62 for the period. A user who is deniedaccess to a resource will not receive fresh lock-access data 62 for theperiod and instead will bear expired lock-access data. The risk ofunauthorized access is thus inversely proportional to the frequency ofregeneration. That is, if lock-access data 62 for each user isregenerated each night to grant access for the following day, then auser whose permission is revoked for a particular resource will stillhave access for, at most, one day following the revocation. Tocomplement this technique, particularly when a short period ofregeneration is selected, the database can further store a regenerationend time for each user, after which lock-access data 62 will no longerbe regenerated. This can allow for fresh lock-access data 62 to begenerated periodically (e.g., daily, weekly, etc.) within a largerperiod (e.g., one month), and may be useful in that the administratordoes not have to return to the server 12 to actively revoke apermission. In an example use case, a regeneration end time foremployees is set to one year and a regeneration end time for contractorsis set to the time in the future that the contract is expected to end.

In another example of revoking permissions, the lock data 58 includesversion data that is provided to the lock controllers 14. Thelock-access engine 60 updates the version data when access permission toany user or users is revoked. Users who are not revoked obtainlock-access data 62 containing the updated version data, which matchesthat sent by the lock controllers 14, thereby permitting access. Userswhose permissions are revoked can only present lock-access data thatincludes non-updated version data, and the lock controllers 14 areconfigured to ignore and/or log access requests bearing non-matchingversion data.

The above two techniques for revoking permissions can be usedindependently or combined.

The server 12 further includes a logging engine 64 configured to receivelog data from deployed lock controllers 14 and to save long-term lockaccess logs 66.

The server 12 further includes an admin engine 68 configured to receiveupdates to user account data 56 and lock data 58. The admin engine 68 isconfigured to create, modify, and delete user accounts, as well aslogically create, modify, and delete lock controllers 14. Further, theadmin engine 68 is configured to set access permissions by creatinglock-access data 62 for various combinations of users and lockcontrollers and to revoke access permissions, as needed, by updatingversion data and/or setting regeneration expiry times.

FIG. 3 shows data structures for lock data 58, lock-access data 62, anduser account data 56.

An element of lock data 58 is mapped to a lock controller 14 by way of alock controller unique identifier 80, which can be a serial number, analphanumeric code, a hash, or similar kind of unique or pseudo-uniqueidentifier. Lock data 58 further includes version data 82, which is anumber, alphanumeric code, or similar data element representative of thecurrent version of access for the lock controller 14. Version data 82can be changed to revoke access to a particular user by informing allother users of the new version, but not informing the particular user.Lock data 58 can further include a text description of the lockcontroller 14 or the respective resource 20 and a location 86 (e.g.,geographic coordinates) of the lock controller 14. The lock data 58 mayalso store an access limit 104 for each lock controller to specify themaximum access time that will provided in schedule data, so as to forceusers to obtain fresh lock-access data more frequently for highly secureresources. That is, the access limit 104 defines the maximum validityperiod for a particular element of lock-access data 62 (e.g., 24 hoursfor highly secure locations, one month for lower security locations,etc.). This ensures that users have their credentials authenticated atfrequency commensurate with the security required for the particularresource.

An element of user account data 56 is mapped to a user by way of a userunique identifier 90, which can be a number, an alphanumeric code, ahash, or similar kind of unique or pseudo-unique identifier. The userunique identifier 90 can correspond to the user or the wireless mobiledevice 16 assigned to the user. Examples of user unique identifiers 90include an email address, an employee number, a username, a hash of theuser's name and birthdate, a hash of the username and/or password, aphone number, a phone IMEI, a MAC address, and similar. User accountdata 56 further stores a username 92 and password 94 for each user toauthenticate with the server 12, and may store additional informationabout the user, such as name 96, company 98, division 100, and similar.When access-data regeneration is used, the user account data 56 may alsostore a regeneration expiry time 102 for each user, so that permissionmay be globally granted/revoked for each user.

The lock-access data 62 defines access permissions to a physicalresource 20 for a user of a wireless mobile device 16. Accordingly, eachelement of lock-access data 62 includes a lock controller uniqueidentifier 80 of the specific lock controller 14/physical resource 20for which access is being granted, version data (if used) for thespecific a lock controller 14, access schedule data 110 that includes atleast one start time and at least one end time, and may further includea user unique identifier 90 for the specific user or device beinggranted access. The schedule data 110 can include a date and/or time ofday defining the beginning and ending of a period of permitted accessfor a particular user. When the lock-access data 62 is provided by thewireless mobile device 16 to the lock controller 14, the lock controller14 checks that the received lock-access data 62 matches comparable datastored at the lock controller 14 before opening the lock. That is, thelock controller 14 only opens the lock 18 after the identity and timeconditions are met.

FIG. 4 shows a block diagram of a wireless mobile device 16. Thewireless mobile device 16 is one example of a wireless mobile devicethat can be used with the system 10.

The wireless mobile device 16 includes a network interface 120, awireless interface 122, a user interface 124, memory 126, and aprocessor 128. The network interface 120 is configured for bidirectionaldata communications via the computer network 24. The network interface120 includes a network adaptor and driver suitable for the type ofnetwork 24. The wireless interface 122 includes a short-rangecommunications interface, such those discussed above (e.g., Bluetooth,BLE, etc.). The network interface 120 and the wireless interface 122 maybe the same interface configured differently. The user interface 124includes a display device, a touchscreen, a keyboard, a microphone, aspeaker, or a combination of such. The memory 126 includes anycombination of ROM, RAM, flash memory, magnetic storage, opticalstorage, and similar for storing instructions and data as discussedherein. The processor 128 includes one or more CPUs, microcontrollers,microprocessors, processing cores, field-programmable gate arrays FPGAs,and similar. All or some of the memory 126 may be integrated with theprocessor 128. The processor 128 and memory 126 cooperate to executeinstructions to cause the wireless mobile device 16 to perform thefunctionality discussed herein.

The wireless mobile device 16 is configured to store the server publickey 30 and further store any lock-access data 62 to be used to gainaccess to physical resources 20. The wireless mobile device 16 canfurther be configured to temporarily store settings data 130 in transitfrom the server 12 to a particular lock controller 14 and log data 132in transit from a particular lock controller 14 to the server 12. Thewireless mobile device 16 is configured to act as a data proxy betweenthe server 12 and the lock controller 14. Hence, the wireless mobiledevice 16 may be required to temporarily store settings data 130 and/orlog data 132 at times when long-range data communications are notavailable through the network interface 120. For example, a physicalresource 20 may be located outside of cellular coverage and the wirelessmobile device 16 holds log data destined for the server 12 until thewireless mobile device 16 returns to coverage. Likewise, the settingsdata destined to the lock controller 14 may be transmitted to thewireless mobile device 16 before the wireless mobile device 16 leavescoverage.

The wireless mobile device 16 further includes an application 134 and anencryption engine 136. The application 134 can be configured to providehuman-intelligible descriptions for any stored lock-access data 62, suchas resource description and location, or to hide lock-access data 62from the user. Similarly, the application 134 can be configured toprovide human-intelligible descriptions for any stored server publickeys 30, such as owner name, or to hide server public keys 30 from theuser. The application 134 is configured to manage connections andaccount credentials with the server 12 and to receive lock access data62 from the server 12. The application 134 is further configured tointerface with the encryption engine 136.

The application 134 can be further configured to accept statusnotifications from lock controllers 14 in vicinity of the wirelessmobile device 16 and to respond by retrieving data (e.g., log data) froma lock controller 14 and transporting such data to the server 12 or byobtaining data (e.g., version data or other settings data 130) from theserver 12 and transporting such data to the lock controller 14. Theapplication 134 can be configured to facilitate such transport of datairrespective of whether a particular lock controller 14 is to beaccessed by the wireless mobile device 16. That is, a wireless mobiledevice 16 can act as a wireless data proxy between electronic lockcontrollers 14 and the server 12. Transporting these kinds of data canbe hidden from the user, as no user interaction is required. Theapplication 134 can further be configured to use the encryption engine136 to encrypt data bound a lock controller 14 using that lockcontroller's public key.

The encryption engine 136 is configured to use the server's public key30 to validate the authenticity of any certificate provided byelectronic lock controllers 14, and to encrypt lock-access data 62received from the server 12 using validated public keys of the lockcontrollers 14. The application 134 is configured to transmit anymessages containing encrypted lock-access data 62 to the respectiveelectronic lock controllers 14 via the wireless interface 122.

The application 134 can further be configured to handlediscovery/pairing with electronic lock controllers 14, as well as setupand expiry of short-range communications sessions with electronic lockcontrollers 14, according to the particular communications scheme used(e.g., Bluetooth, BLE, etc.)

FIG. 5 shows a block diagram of an electronic lock controller 14. Theelectronic lock controller 14 is one example of an electronic lockcontroller that can be used with the system 10.

The electronic lock controller 14 includes a short-range wirelessinterface 140, a lock control interface 142, a power supply 144, memory146, and a processor 148. The short-range wireless interface 140includes a short-range communications interface, such those discussedabove (e.g., Bluetooth, BLE, etc.), configured for communication withwireless mobile devices 16 in vicinity of the electronic lock controller14. The memory 146 includes any combination of ROM, RAM, flash memory,magnetic storage, optical storage, and similar for storing instructionsand data as discussed herein. The processor 148 includes one or moreCPUs, microcontrollers, microprocessors, processing cores,field-programmable gate arrays FPGAs, and similar. All or some of thememory 146 may be integrated with the processor 148. The processor 148and memory 146 cooperate to execute instructions to cause the electroniclock controller 14 to perform the functionality discussed herein. Inthis embodiment, the electronic lock controller 14 notably excludes anylong-range wired/wireless communications interface.

The lock control interface 142 is configured to provide signals to thelock 18 and may also be configured to receive signals from the lock 18.The lock control interface 142 can include an I/O port/bus or similar.Examples of signals that can be sent to the lock 18 include an unlockingsignal that unlocks the lock 18 and a locking signal that locks the lock18. Examples of signals that can be received from the lock 18 include astatus signal indicating whether the lock 18 is locked or unlocked. Inthis example, the lock 18 includes driving circuity and an electricalactuator 160 such as motor, solenoid, or similar that convertselectrical power into mechanical movement of the lock 18 according tosignals received from the lock control interface 142. In other examples,the lock control interface 142 includes one or both of such drivingcircuity and electrical actuator.

The power supply 144 is configured to provide power to the electroniclock controller 14. The power supply 144 may also be configured toprovide power to the lock 18 if the lock does not have its own powersupply. Examples of suitable power supplies 144 include batteries, windgenerators, solar panels, a combination of such, and the like. Multiplepower supplies 144 of the same or different types can be provided forredundancy.

The lock controller 14 is configured to store a digital certificate 36,the digital certificate 36 being digitally signed by the private key 32of a server 12 previously. The digital certificate 36 includes publicand private keys for the lock controller 14. The lock controller 14 isfurther configured to store the public key 30 of the server 12. Theelectronic lock controller 14 further stores its identifier 80, so thatthe lock controller 14 can consider only lock-access data containing theidentical identifier 80 as valid.

The electronic lock controller 14 includes lock control logic 150 and anencryption engine 152. The control logic 150 is configured to transmitthe public key of the digital certificate 36 to wireless mobile devices16 through the wireless interface 140, so that the wireless mobiledevices 16 may securely communicate with the lock controller 14. Thecontrol logic 150 is further configured to control the encryption engine152 to decrypt encrypted lock-access data contained in messages receivedfrom wireless mobile devices 16 via the wireless interface 140.Decryption is performed using the private key of the digital certificate36, so as to obtain decrypted lock-access data. The control logic 150 isfurther configured to validate the authenticity of any receivedlock-access data using the public key 30 of the server 12. The lockcontrol logic 150 is also configured to check authenticated lock-accessdata against internal settings data 130 and to the control the lockcontrol interface 142 to unlock the physical lock 18, as permitted bylock-access data, so as to grant access to the physical resource 20.

Settings data 130 stores settings of the electronic lock controller 14,including at least the internal time 162 of the lock controller 14. Thelock control logic 150 references the internal time 162 when determiningwhether to actuate the lock 18 based on received lock-access data.Settings data can also include version data 154 for comparison withversion data received in lock-access data from a wireless mobile device16 requesting access to the physical resource. The lock control logic150 is configured to compare received version data with stored versiondata 154 as a condition to grant access to the physical resource.Version data is thus a check as to whether the user of the wirelessmobile device 16 is still permitted to access the resource after aversion update has been made to deny one or more other users access tothe resource.

The lock control logic 150 is further configured to record instances ofaccess to the physical resource as log data 132. Further, the lockcontrol logic 150 can be configured to use the encryption engine 152 toencrypt the log data 132 using the public key 30 of the server 12. Thelock control logic 150 transmits messages containing log data, whetherencrypted or not, to any wireless mobile devices 16 in vicinity of thewireless interface 140 for transport back to the server 12.

The lock control logic 150 can be configured to broadcast a status ofany data stored at the electronic lock controller 14, including settingsdata 130 and log data 132. Status for settings data can include anindication of the last time that the lock controller's internal time 162was adjusted or an indication that a time check and potential adjustmentis required. It is contemplated that a lock controller's internal timemay be incorrect due to a variety of reasons, such as clock drift, powerloss events, daylight savings mismatches, and similar. Maintaining anaccurate internal time advantageously allows for more thorough controlof access to the resource, in that expired or early lock-access datacannot be used to gain access.

A status notification for version data 154 can include an indication ofthe last time that the version data 154 was updated or an indication ofthe version data itself.

A status notification for log data 132 can include an indication of newlog data requiring transport to the server 12 and may further include anindication of a number/quantity of such log data.

Multiple of the above status notification examples can be combined intoa single status notification that is broadcasted. The specific form ofany broadcasted status notifications can be varied and is notparticularly limited. Status notifications may be broadcasted inplaintext or as encrypted by, for instance, the public key 30 of theserver 12. It is advantageous that the broadcasting of statusnotifications allows the lock controllers 14 to not be always connectedto the network 24. This makes large deployments more practical where,rather than connecting each lock controller 14 to the internet, aplurality of wireless mobile devices 16 are used to relay data betweenthe server 12 and the lock controllers 14. Instead of one user or asmall group of users moving from lock to lock to maintain the lockcontrollers, the users themselves maintain the lock controllers withoutany intentional action needed.

The lock control logic 150 can be configured to receive messagescontaining encrypted settings data 130 from wireless mobile devices 16via the wireless interface 140. The lock control logic 150 then uses theencryption engine 152 to decrypt the encrypted settings data using theprivate key of the certificate 36 and validates authenticity of thesettings data using the public key 30 of the server 12. If the settingsdata 130 can be authenticated, then the lock control logic 150 updatesthe respective setting or settings of the lock controller 14.

FIGS. 6-9 show processes according to the present invention. Theseprocesses may be used with the system 10 or with another system. Theprocesses will be discussed in the context of the system 10 for sake ofexplanation.

FIG. 6 shows process for setting up the server 12, wireless mobiledevices 16, and electronic lock controllers 14.

At step 200, a public and private key pair for the server is loaded ontothe server 12 in a secure manner.

At step 202, a digital certificate in loaded onto each electronic lockcontroller 14. Each electronic lock controller 14 has its own uniquedigital certificate and each digital certificate has been digitallysigned by the private key of the server 12. Each digital certificate hasa different public and private key pair for the respective theelectronic lock controller 14. Signing and certificate loading ispreferably done in a secure environment, such as at a manufacturingfacility or lock deployment facility.

At step 204, the public key of the server 12 is loaded onto eachelectronic lock controller 14. This can be done with step 202 or atanother time, and is preferably done in a secure environment, such as ata manufacturing facility or lock deployment facility.

At step 206, the server's public key is distributed to each wirelessmobile device 16. This can be done at any time and can be doneperiodically, as new devices are deployed and existing ones updated. Forexample, the server's public key can be transmitted to a wireless mobiledevice 16 after the user at the wireless mobile device 16 logs intohis/her user account with the server 12.

The result of the setup process of FIG. 6 is that the server 12digitally signs messages for each lock controller 14, passes thesemessages to respective wireless mobile devices 16, and that such devices16, 14 can validate the authenticity of such data using the server'spublic key. Moreover, secure communications can be established between awireless mobile device 16 and an electronic lock controller 14 using thesigned digital certificate provided to the electronic lock controller14.

FIG. 7 shows a process for securely controlling an electronic lockcontroller 14 to unlock its lock or to perform another action, after thesetup process of FIG. 6 has been completed.

At step 210, the server 12 generates lock-access data for access to aspecific physical resource guarded by a specific lock controller 14 by aspecific user in possession of a wireless mobile device 16. Generationof lock-access data can be on demand as triggered, for example, by theuser logging into his/her account with the server 12. Generation oflock-access data can alternatively or additionally be periodic, ascontrolled by a regeneration period and, optionally, a longerregeneration end time. The server 12 digitally signs all lock-accessdata with its private key.

At step 212, the server 12 transmits the signed lock-access data to thewireless mobile device 16 over a secure communications channel (e.g.,TLS).

At some time in the future, the wireless mobile device 16 moves into thevicinity of the electronic lock controller 14. The user then expressesan intention through the mobile wireless device 16 to access thephysical resource protected by the lock controller 14. This can be donevia an application at the mobile wireless device 16, such as theapplication discussed above. In response, the mobile wireless device 16and lock controller 14 establish communications though a short-rangewireless interface and session encryption parameters are shared, at step214. Session encryption parameters include one or more randomizedsession variables. If the mobile wireless device 16 does not yet havethe lock controller's certificate (e.g., this is the first instance ofcommunication between the two devices), the mobile wireless device 16requests it and the electronic lock controller 14 transmits itscertificate to the wireless mobile device 16, at step 214. The mobilewireless device 16 can save certificates for the future use.

Next, at step 216, the wireless mobile device 16 uses the public key ofthe server 12 to validate the authenticity of the public key receivedfrom the electronic lock controller 14, as the certificates andtherefore public keys distributed to legitimate electronic lockcontrollers 14 were digitally signed by the server's private key. Thisverifies that the lock controller 14 is not an impostor that has beenset up, for instance, to steal valid, signed lock-access data from thesystem.

At step 218, the wireless mobile device 16 encrypts the lock-access datausing the public key of the electronic lock controller 14. A random orpseudorandom session identifier may also be used when encrypting thelock-access data. A hardware-based random number generator can be usedto generate session identifiers.

Then, at step 220, after validating the authenticity of the public keyreceived from the lock controller 14, the wireless mobile device 16transmits the encrypted lock-access data within a message to theelectronic lock controller 14. It is noteworthy that this transmissiondoes not rely on other or additional wireless encryption, such as thatafforded by Bluetooth pairing, Wi-Fi WPA2, etc.

The electronic lock controller 14 receives the message containing theencrypted lock-access data, at step 222, and decrypts the encryptedlock-access data using its private key (and the session identifier, ifused). The lock controller 14 then validates the authenticity of thedecrypted lock-access data using the public key of the server 12, aslegitimate lock-access data previously digitally signed by the serverusing its private key.

Next, at step 224, the lock controller 14 checks the decryptedlock-access data against its internal data, such as its identity,schedule data, and version data. One condition for unlocking the lockoperated by the lock controller 14 is the lock controller 14 confirmingthat a lock-controller identifier 80 contained in the lock-access datamatches the lock-controller identifier 80 stored in the lock controller14. That is, the lock controller 14 only responds to lock-access datathat correctly identifies the lock controller 14.

Internal time maintained by the lock controller 14 can be compared tostart and end times for permitted access contained in lock-access data.For instance, the lock is only unlocked when the lock controller'sinternal time is between start and end times of the schedule data.Version data is an arbitrary number, code, token, or similar, asdiscussed above, that represents the lock-access data as being the mostrecent available from the perspective of the lock controller 14. Forinstance, the lock is only unlocked when the version data provided inthe lock-access data matches the lock controller's own version data.

At step 226, the electronic lock controller 14 unlocks the physicallock, if permitted by the check performed to the lock-access data, atstep 224. If the condition or conditions evaluated in step 224 result ina denial of access, other action can be taken at step 226, as discussedelsewhere herein. Moreover, it is contemplated that unlocking in merelyone action that can be performed on the lock. Hence, step 226 canperform alterative or additional actions to unlocking, such as locking.Step 226 can also include logging the access or other action taken byrecording, for example, the user identifier, time, and type of access orattempted access.

As can be understood from the process of FIG. 7, the lock controller 14only responds to commands provided by a wireless mobile device 16 whensuch commands can be validated as being permitted by the server 12. Thisallows central control of physical access to distributed physicalresources. If a specific user is to be denied access, then this can beeffected at the server 12 by withholding lock-access data containingcurrent access start/end times and/or withholding lock-access datacontaining current version data. This can be done on the basis ofindividual lock controllers 14, so that access can be granted andrevoked, as needed.

In some embodiments, lock-access data can be set to have a very shorttime window of validity, necessitating a user to authenticate with theserver very near to the time (and place) of access to the physicalresource. This may improve security in some situations where networkconnectivity is available near the physical resource. In any event, thevalidity time of lock-access data can be selected to ensure securitywhile at the same time allowing users enough time to physically reachthe resource and unlock it.

FIG. 8 shows a process for securely updating data of the lockcontrollers 14. This process can be used to update any combination ofversion data, schedule data, other setting data at the lock controllers14.

At step 240, a lock controller 14 broadcasts a notification of a statusof its data. A status can be an indication that data at the lockcontroller 14 requires updating. Alternatively, the status can simply bean indication of the age of the data at the lock controller 14. Thebroadcasted status can be obfuscated or encrypted.

At step 242, a wireless mobile device in the vicinity of the lockcontroller 14 receives the broadcast and forwards the status to theserver 12.

The server 12 then checks the status and generates update data ifneeded, at step 244. For example, the status indicates the internal timeof the lock controller 14 and the server 12 compares the internal timeto its own time and generates a new internal time or time correction tosend to the lock controller 14 if the lock controller's time is notaccurate enough. In another example, the status represents the versiondata at the lock controller 14 and the server 12 determines whether theversion data requires an update. The server 12 signs update data withits private key.

Update data is then transmitted to the wireless mobile device 16, atstep 246.

If this is the first interaction between the wireless mobile device 16and the lock controller 14, the wireless mobile device 16 receives andvalidates the authenticity of the lock controller's certificate, insteps 214 and 216, as discussed above. Step 214, also includes sharingone or more session encryption parameters.

The wireless mobile device 16 uses the lock controller's public key toencrypt the update data, at step 250, before transmitting a messagecontained the encrypted update data to the lock controller 14, at step252.

The lock controller 14 receives the message containing the encryptedupdate data, decrypts the update data, and uses the server's public keyto validate the authenticity of the update data, at step 254.

If the update data is successfully validated, then the lock controller14 implements the update represented by the update data, at step 256.The lock controller 14 thus updates its internal time, version number,or other setting so that access permissions are made current.

The update process of FIG. 8, or at least steps 244-256 of the process,can be performed before the access granting process of FIG. 7 for acommunicating wireless mobile device 16 and lock controller 14, so thataccess permissions are made current before any access request by thewireless mobile device 16 is processed. This is useful because, forexample, it may be the case that the wireless mobile device 16facilitating the update to the lock controller 14 is to be denied accessby the same update.

FIG. 9 shows a process for securely collecting log data from the lockcontrollers 14. The log data is indicative of past access to thephysical resource via the electronic lock controller 14 and/or otheractions taken by the user and lock controller 14.

At step 266, the wireless mobile device 16 requests from the server 12 astatus of captured log data for the lock controller 14 with which thewireless mobile device 16 is communicating. In response, at step 268,the server 12 transmits to the wireless mobile device 16 a statusindication of log data present on the server 12 for this lock controller14. Log data status can include a number of log items stored at theserver 12, for example.

At step 270, the lock controller 14 broadcasts a status notification forits log data. The status can be an indication of a quantity of log dataat the lock controller 14. The broadcasted status can be obfuscated orencrypted. Step 270 can occur before or after steps 266 and 268.

At step 271, the wireless mobile device 16 receives the broadcast andcompares the log-data indication received from the server 12 with thatreceived from the lock controller 14 to determine if the server 12 lacksany log data. For example, the wireless mobile device 16 may determinethat the lock controller 14 has indicated that it has more log itemsthan the server 12 has, and hence that the additional new log datashould be obtained from the lock controller 14 and sent to the server12. The number of log items is used for the comparison, in this example.In other examples, an amount of log data (e.g., kB, MB, etc.) or a mostrecent log item timestamp can be used.

If there is new log data to obtain, at step 272, the wireless mobiledevice 16 sends a request for at least the new log data to the lockcontroller 14.

At step 274, the lock controller 14 encrypts the log data using thepublic key of the server 12 before transmitting a message containing theencrypted log data to the wireless mobile device 16, at step 276.

Then, at step 278, the wireless mobile device 16 transmits the encryptedlog data to the server 12, which receives the encrypted log data and canthen decrypt the log data using its private key, at step 280, store thelog data, process it, and/or present the log data. In the case of poormobile network coverage, step 278 may occur after the mobile wirelessdevice 16 returns to coverage.

Further additional or alternative aspects of the present invention aredescribed in the following.

Each time a user logs into the his/her account at the server 12, theserver 12 may force the user's wireless mobile device 16 to delete allstored lock-access data and download fresh lock-access data from theserver 12.

The application 134 at the wireless mobile device 16 can be configuredto routinely delete expired lock-access data 62.

The lock control logic 150 of a lock controller 14 can be configured torequire two or more elements of validated lock-access data 62 in orderto provide access to the physical resource to two or more differentusers at the same time. This adds an additional layer of security, inthat two or more different users must be present at the lock controller14 to gain access to the resource, reducing the risk of theft or otherundesirable occurrence.

FIG. 10 shows another embodiment of an electronic lock controller 300.This embodiment is similar to the embodiment of FIG. 5 and onlydifferences will be discussed in detail. The lock controller 300includes a network interface 302 configured for bidirectional datacommunications via the computer network 24. The network interface 302includes a network adaptor and driver suitable for the type of network24. This allows the electronic lock controller 300 to communicate withwireless mobile devices 16 through the internet or other component ofthe network 24. As such, access can be granted to a physical resourceoutside of the proximity of the respective lock controller 300. Forinstance, a user with a wireless mobile device 16 can open a lock from alocation remote to the lock, so as to grant physical access to anotheruser who is physically located at the lock.

In view of the above, numerous advantages of the present inventionshould be apparent. Access to physical resources, which may be remote orinfrequently accessed, can be readily centrally controlled whilemaintaining a fully set of access permissions only at the server.Further, the lock controllers need not be aware of the full set ofaccess permissions for all users, and simply need to respond to receiveddigitally signed lock-access data. The lock controllers do not evenrequire their own data connectivity and instead can use any nearbywireless mobile device as a conduit to the server. In addition, revokingaccess to one or more users is readily achievable without having todistribute new keys.

Reliance on network-specific encryption and authentication mechanisms isavoided, as many, such as WPA and Bluetooth 4.0, have been shown to bevulnerable. In contrast, the present invention is transport-agnostic byvirtue of the use of digital certificates. The present invention canoperate without dependence on Bluetooth or WLAN security, and hence canbe readily ported to multiple (and future) wireless technologies, whileavoiding the pitfalls of current wireless security protocols.

The use of digital certificates and the broadcasting of statusnotifications enables multiple devices to control/update any lockcontroller, with the users of such devices being aware of theupdate/control. Dependence on special manager/admin devices is reducedor eliminated. Further, the broadcasting of status notifications avoidseach mobile device connecting to a lock controller having to check forlog data or update requirements. Polling is avoided. Instead, mobiledevices within range are notified of lock-controller state changes andrespond appropriately.

Moreover, the use of digital certificates and version data enableseffective scaling to many users (e.g., thousands or more users inenterprise deployment of resources), as each lock controller need notknow each user's permissions. Rather, each lock controller need onlyrespond to valid lock-access data. Further, a lock controller can beconfigured to respond only to multiple elements of lock-access dataprovided by different devices for even greater security.

In addition, the present invention provides for real-time unlockingdecisions based on a mobile device's connectivity with a server, and noton a lock-controller's ability to connect to the server. While theforegoing provides certain non-limiting examples, it should beunderstood that combinations, subsets, and variations of the foregoingare contemplated. The monopoly sought is defined by the claims.

What is claimed is:
 1. A process for providing secure access to aphysical resource, the process comprising: loading a digital certificateonto an electronic lock controller, the digital certificate beingdigitally signed by a private key of a server, the digital certificatehaving a public key of the electronic lock controller and acorresponding private key of the electronic lock controller, theelectronic lock controller operably connectable to a physical lock thatrestricts access to the physical resource; loading onto the electroniclock controller a public key of the server that corresponds to theprivate key of the server; distributing the public key of the server toa wireless mobile device; the server signing lock-access data with theprivate key of the server, the lock-access data defining physical accesspermission to the physical resource by a user of the wireless mobiledevice; transmitting the lock-access data to the wireless mobile devicevia a computer network; the wireless mobile device encrypting thelock-access data using the public key of the electronic lock controllerand providing the encrypted lock-access data in a message for theelectronic lock controller; when the wireless mobile device is invicinity of the electronic lock controller, the wireless mobile devicetransmitting the message containing the encrypted lock-access data tothe electronic lock controller; the electronic lock controller receivingthe message, decrypting the encrypted lock-access data using the privatekey of the electronic lock controller to obtain the lock-access data,and validating authenticity of the lock-access data using the public keyof the server; after validating the authenticity of the lock-accessdata, the electronic lock controller unlocking the physical lock ifpermitted by the lock-access data to grant the user access to thephysical resource.
 2. The process of claim 1, further comprising: whenthe wireless mobile device is in vicinity of the electronic lockcontroller, the electronic lock controller transmitting the public keyof the electronic lock controller to the wireless mobile device; andafter receiving the public key of the electronic lock controller, thewireless mobile device using the public key of the server to validateauthenticity of the public key of the electronic lock controller.
 3. Theprocess of claim 1, further comprising the electronic lock controllerencrypting log data indicative of past physical access to the physicalresource using the public key of the server and transmitting a messagecontaining the encrypted log data to the wireless mobile device forcommunication over the computer network from the wireless mobile deviceto the server.
 4. The process of claim 1, further comprising thewireless mobile device encrypting settings data using the public key ofthe electronic lock controller and providing the encrypted settings in amessage for the electronic lock controller, and the electronic lockcontroller receiving the message, decrypting the encrypted settings datausing the private key of the electronic lock controller to obtain thesettings, validating authenticity of the settings data using the publickey of the server, and updating at least one setting of the electroniclock controller based on the settings data.
 5. The process of claim 4,wherein the settings data includes version data for storage at theelectronic lock controller, the process further comprising includingversion data in the lock-access data, the electronic lock controllermatching version data stored at the electronic lock controller withversion data received in the lock-access data as a condition forpermitting access to the physical resource.
 6. The process of claim 5,wherein the lock-access data includes a unique identifier of theelectronic lock controller, a start time defining a beginning of aperiod of permitted access, an end time defining an end of the period ofpermitted access, and the version data.
 7. The process of claim 4,further comprising the server digitally signing the settings data usingthe private key of the server before transmitting the settings data tothe wireless mobile device.
 8. The process of claim 1, wherein thelock-access data includes a unique identifier of the electronic lockcontroller, a start time defining a beginning of a period of permittedaccess, an end time defining an end of the period of permitted access,the process further comprising periodically regenerating the lock-accessdata with updated start and end times to allow for continued access tothe physical resource.
 9. The process of claim 8, further comprisingceasing to regenerate the lock-access data to deny access to thephysical resource.
 10. The process of claim 1, further comprising theelectronic lock controller broadcasting to any wireless mobile device invicinity a notification of a status of data of the electronic lockcontroller requiring transport or update.
 11. The process of claim 1,further comprising: loading a unique digital certificate onto each of aplurality of electronic lock controllers including the electronic lockcontroller, each digital certificate being digitally signed by theprivate key of a server, each digital certificate having a public key ofa respective electronic lock controller and a corresponding private keyof the respective electronic lock controller, each electronic lockcontroller operably connectable to a respective physical lock thatrestricts access to a respective physical resource; loading onto eachelectronic lock controller the public key of the server; anddistributing the public key of the server to a plurality of wirelessmobile devices including the wireless mobile device.
 12. A system forproviding secure access to a physical resource, the system comprising: aserver including: memory configured to store a public key of the serverand a corresponding private key of the server; a network interfaceconfigured for communication via a computer network; a processorconfigured to digitally sign lock-access data with the private key ofthe server, the lock-access data defining physical access permissions tothe physical resource for users of wireless mobile devices, theprocessor further configured to transmit the lock-access data torespective wireless mobile devices via the network interface; anelectronic lock controller operably connected to a physical lock thatrestricts access to the physical resource, the electronic lockcontroller including: memory configured to store a digital certificate,the digital certificate being digitally signed by the private key of aserver, the digital certificate having a public key of the electroniclock controller and a corresponding private key of the electronic lockcontroller, the memory further configured to store the public key of theserver; a wireless interface configured for communication with wirelessmobile devices in vicinity of the electronic lock controller; aprocessor configured to transmit the public key of the electronic lockcontroller to wireless mobile devices via the wireless interface, theprocessor further configured to decrypt encrypted lock-access datacontained in messages received from wireless mobile devices via thewireless interface using the private key of the electronic lockcontroller to obtain lock-access data, the processor further configuredto validate authenticity of lock-access data using the public key of theserver; the processor further configured to unlock the physical lock aspermitted by authenticated lock-access data to grant respective usersaccess to the physical resource; a wireless mobile device including:memory configured to store the public key of the server; a wirelessinterface configured for communication with electronic lock controllersin vicinity of the wireless mobile device; a network interfaceconfigured for communication with the server via the computer network; aprocessor configured to use the public key of the server to validateauthenticity of public keys of electronic lock controllers received fromelectronic lock controllers via the wireless interface, the processorfurther configured to encrypt lock-access data received from the serverusing public keys of the electronic lock controllers and transmitmessages containing encrypted lock-access data to respectiveauthenticated electronic lock controllers via the wireless interface.13. The system of claim 12, further comprising a plurality of electroniclock controllers including the electronic lock controller forrestricting access to respective physical resources, and furthercomprising a plurality of wireless mobile devices including the wirelessmobile device.